Cylindrical battery cells, battery packs, vehicles, and current collectors

Abstract

This invention provides a cylindrical battery cell, a battery pack, a vehicle, and a current collector. The cylindrical battery cell includes: a wound-type electrode assembly having a structure in which a first electrode plate and a second electrode plate, both sheet-like, are wound in one direction, sandwiching a separator; the first electrode plate includes a first uncoated area at the end of its long side without an active material layer; the first uncoated area forms multiple wound turns relative to the center of the electrode assembly and is exposed to the outside of the separator, thus serving itself as an electrode connector; a battery can having an opening for receiving the electrode assembly and a partially closed portion disposed on the opposite side of the opening; the battery can being electrically connected to the second electrode plate; a current collector electrically connected to the first uncoated area of ​​the first electrode plate and having a fusible portion that is cut off during overcurrent flow; and a battery cell terminal connected to the current collector through a through-hole in the closed portion of the battery can.

Description

Technical Field

[0001] This disclosure relates to a cylindrical battery cell, a battery pack including the cylindrical battery cell, and a vehicle. Background Technology

[0002] Secondary batteries are widely used not only in portable devices, but also in electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by electric power sources, due to their ease of application in various products and electrical characteristics such as high energy density.

[0003] This type of secondary battery has attracted attention due to its major advantages of significantly reducing the use of fossil fuels and producing no energy-consuming byproducts, making it a new eco-friendly and energy-efficient energy source.

[0004] Currently widely used types of secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of this unit-type secondary battery cell is approximately 2.5V to 4.5V.

[0005] Therefore, when a higher output voltage is required, multiple battery cells can be connected in series to form a battery pack. Alternatively, a battery pack can be manufactured by connecting multiple battery cells in parallel, depending on the required charge / discharge capacity. Thus, the number of battery cells included in a battery pack and the type of electrical connection can vary depending on at least one of the required output voltage or charge / discharge capacity.

[0006] Meanwhile, the secondary battery cells include cylindrical, prismatic, and pouch-type battery cells. Cylindrical battery cells are manufactured by winding the positive and negative electrodes, along with an insulator or separator inserted therebetween, to form a wound-core electrode assembly, which is then inserted into a battery can along with the electrolyte.

[0007] Here, when the battery can is connected to the negative or positive terminal (usually the negative terminal) and has polarity, insulation between the battery can and the wound electrode assembly is necessary.

[0008] Meanwhile, with the increasing application of cylindrical battery cells in electric vehicles, the form factor of cylindrical battery cells is also increasing. That is, compared to cylindrical battery cells with form factors of 18650 and 21700, the diameter and height of cylindrical battery cells are larger. This increased form factor leads to increased energy density, enhanced safety against thermal runaway, and improved cooling efficiency.

[0009] Here, as the form factor increases, the need to protect cylindrical battery cells from overcurrent also increases. As one embodiment, a fuse can be formed on the current collector. However, when a fuse is formed on the current collector, foreign matter generated when the fuse is cut off by an overcurrent may flow into the wound electrode assembly. In this case, the separator may be damaged by the foreign matter, which may cause an internal short circuit. Summary of the Invention

[0010] Technical issues

[0011] This disclosure aims to address the problems of the prior art, and therefore aims to provide a cylindrical battery cell that can prevent foreign matter generated when the fuse is cut from flowing into the wound electrode assembly by appropriately adjusting the position of the fuse portion in the current collector. This disclosure also aims to provide a battery pack and a vehicle including the cylindrical battery cell.

[0012] This disclosure also aims to provide a battery pack made using cylindrical battery cells with an improved structure, and a vehicle including the battery pack.

[0013] However, the technical problems to be solved by this disclosure are not limited to those described above, and those skilled in the art will clearly understand these and other problems based on the following description.

[0014] Technical solution

[0015] In one aspect of this disclosure, a cylindrical battery cell is provided, comprising: a wound electrode assembly having a structure in which a first electrode plate and a second electrode plate, both sheet-like, are wound in one direction with a separator sandwiched between them; the first electrode plate including a first uncoated area at the end of its long side without an active material layer coated thereon; the first uncoated area forming a plurality of wound turns relative to the center of the electrode assembly and exposed to the outside of the separator, thereby serving itself as an electrode connector; a battery can having an opening for receiving the electrode assembly and a partially closed portion disposed on the opposite side of the opening; the battery can being electrically connected to the second electrode plate; a current collector electrically connected to the first uncoated area of ​​the first electrode plate and having a fusible portion that is cut off when an overcurrent flows; and a battery cell terminal connected to the current collector through a through-hole in the closed portion of the battery can.

[0016] Preferably, at least a portion of the bottom surface of the battery cell terminal may be formed with a flat portion parallel to the inner surface of the closed portion of the battery can, and the current collector may be connected to the flat portion of the battery cell terminal.

[0017] Preferably, the manifold can be attached to a connecting surface formed by bending the end of the first uncoated area.

[0018] Preferably, the electrode assembly may include a welding target area along the radial direction of the electrode assembly, and the current collector may be connected to the first uncoated area within the welding target area.

[0019] In one embodiment, the current collector may include: a frame portion disposed at the upper portion of the electrode assembly; an uncoated area connection portion configured to extend inwardly from the frame portion and connect to the first uncoated area; a terminal connection portion spaced apart from the uncoated area connection portion and connected to the battery cell terminal; and a connection portion configured to extend inwardly from the frame portion to connect to the terminal connection portion and having the fusible portion, wherein, under the same current flow conditions, the fusible portion has a larger resistance compared to other areas.

[0020] Preferably, the border portion may have a border shape, wherein at least a portion of the inner region is empty.

[0021] Preferably, the uncoated area connection portion and the terminal connection portion can be electrically connected via the frame portion.

[0022] Preferably, the terminal connection portion may be located at the center of the internal space of the frame portion.

[0023] Preferably, the diameter of the terminal connection portion can be 100% to 110% of the diameter of the hollow portion present in the core of the electrode assembly.

[0024] In one embodiment, the fusible portion may be at least one notch formed in the connecting portion.

[0025] Preferably, the notch may be formed at the end of the connector in the width direction, at the upper surface of the connector, or at the lower surface of the connector.

[0026] Preferably, the notch can be formed as a recess toward the interior of the connection portion in a direction that gradually or continuously reduces the width or thickness of the connection portion.

[0027] Preferably, the minimum width of the fused portion can be from 0.5 mm to 4.0 mm.

[0028] In another embodiment, the fusible portion may be at least one through hole formed in the connection portion.

[0029] Preferably, the maximum width of the through hole can be from 0.2 mm to 6 mm.

[0030] In another embodiment, the fusible portion may be surrounded by a strip.

[0031] Preferably, the strip may contain polyimide (PI) material.

[0032] Preferably, the fused portion may be formed on the connecting portion at a distance of 40% to 90% of the maximum radius of the electrode assembly from the center of the electrode assembly.

[0033] In one embodiment, at least a portion of the first uncoated area may be divided into multiple segments along the winding direction of the electrode assembly.

[0034] Preferably, at least a portion of the plurality of segments may be bent along the radial direction of the electrode assembly.

[0035] Preferably, at least a portion of the plurality of segments may overlap in multiple layers along the radial direction of the electrode assembly.

[0036] In another embodiment, other segments of the plurality of segments may be without bending, and the fused portion may be offset from the unbent segments of the plurality of segments and positioned above the bent segments of the plurality of segments.

[0037] In another embodiment, other segments of the plurality of segments may be cut, and the fused portion may be offset from the cut segment of the plurality of segments and positioned above the bent segment of the plurality of segments.

[0038] Preferably, the welding pattern drawn by solder beads formed on one surface of the terminal connection portion of the current collector can be drawn in the form of surrounding the center of the bottom surface of the battery cell terminal.

[0039] Preferably, the welding pattern can be formed continuously or discontinuously.

[0040] Preferably, the tensile force of the weld formed between the terminal connection portion of the current collector and the bottom surface of the battery cell terminal can be 2 kgf or more.

[0041] Preferably, the conversion diameter of the welding pattern drawn by the solder beads formed on one surface of the terminal connection portion of the current collector can be 2 mm or more. The conversion diameter refers to the diameter of the circle when the area of ​​the welding pattern is converted into the area of ​​the circle.

[0042] In one embodiment, the cylindrical battery cell may further include a cap plate configured to close the opening of the battery can.

[0043] Preferably, the cap plate is electrically decoupled from the electrode assembly and is non-polar.

[0044] Preferably, the closure portion may have a through hole, and the battery cell terminal may be connected to the through hole.

[0045] Preferably, the cylindrical battery cell may further include an insulator inserted between the closure portion and the current collector.

[0046] Preferably, the insulator may comprise an insulating polymer material.

[0047] Preferably, the insulator may be made of an elastic material.

[0048] Preferably, the insulator may have a central hole at its center, and the central hole has a predetermined diameter.

[0049] Preferably, the thickness of the insulator can correspond to the distance between the inner surface of the closure portion of the battery can and the current collector.

[0050] Preferably, the upper surface of the insulator can contact the inner surface of the closed portion of the battery can, and the lower surface of the insulator can contact the upper surface of the current collector.

[0051] In one embodiment, the battery cell terminal may include a terminal insertion portion, and the terminal insertion portion may be inserted into the battery can through the through hole.

[0052] Preferably, the battery cell terminal can be fixed to the through hole while the lower edge of the terminal insertion portion is riveted toward the inner surface of the upper end of the battery can.

[0053] Preferably, the diameter of the central hole in the insulator can be equal to or greater than the diameter of the terminal insertion portion.

[0054] Preferably, the terminal insertion portion of the battery cell terminal can pass through the central hole of the insulator.

[0055] Preferably, the terminal insertion portion of the battery cell terminal can pass through the central hole of the insulator and be electrically connected to the current collector.

[0056] In one embodiment, the cylindrical battery cell may further include: a sealing gasket between the edge of the cap plate and the opening of the battery can, the battery can including a crimped portion press-fitted toward the inside of the battery can in a region adjacent to the opening, and the battery can including a crimped portion extending toward the inside of the battery can and bent to surround the edge of the cap plate and secure the edge of the cap plate together with the sealing gasket.

[0057] Preferably, the crimping portion may be formed in the lower part of the battery can based on the placement of the battery can.

[0058] Preferably, the cap plate may include a vent notch configured to break when the internal pressure of the battery can exceeds a threshold.

[0059] Preferably, the venting notch can be formed on both surfaces of the cap plate, and at least one of a continuous circular pattern, a discontinuous circular pattern, and a linear pattern can be formed on the surface of the cap plate.

[0060] Preferably, the vent can be formed on the bottom of the battery can based on the placement of the battery can, and when the vent can breaks, the gas in the battery can can be discharged through the bottom of the battery can.

[0061] In another embodiment, the cylindrical battery cell may further include a lower current collector connected to the bottom of the electrode assembly.

[0062] Preferably, at least a portion of the edge of the lower current collector can be electrically connected to the rolled edge portion, and at least a portion of the remaining area other than the edge of the lower current collector can be electrically connected to the second uncoated area of ​​the second electrode plate.

[0063] Preferably, at least a portion of the edge of the lower manifold can be electrically connected to the surface of the upper and lower surfaces of the rolled edge that is adjacent to the crimping portion.

[0064] Preferably, the lower manifold and the rolled edge portion can be laser welded.

[0065] In another aspect of this disclosure, a battery pack including at least one cylindrical battery cell is also provided, and a vehicle including at least one battery pack is also provided.

[0066] In another aspect of this disclosure, a current collector is also provided that electrically connects the battery cell terminals on the closure of the battery can of a cylindrical battery cell to an electrode assembly. The current collector includes: a frame portion; an uncoated area connection portion configured to extend inward from the frame portion and connect to an uncoated area of ​​the electrode assembly; a terminal connection portion spaced apart from the uncoated area connection portion, with a space between them; a connection portion configured to extend inward from the frame portion to connect to the terminal connection portion; and a fusible portion formed on the connection portion, which has a larger resistance compared to other areas under the same current applied.

[0067] Beneficial effects

[0068] According to one aspect of this disclosure, by appropriately adjusting the position of the fuse in the current collector, foreign matter generated when the fuse is cut can be prevented from flowing into the core-type electrode assembly.

[0069] According to another aspect of this disclosure, it is possible to provide a battery pack with improved capacity made using cylindrical battery cells with an improved structure, and a vehicle including the battery pack. Attached Figure Description

[0070] Figure 1 This is a perspective view of a cylindrical battery cell according to one embodiment of the present disclosure.

[0071] Figure 2 It is shown Figure 1 A three-dimensional cross-sectional view of the central section of a cylindrical battery cell.

[0072] Figure 3 This is a cross-sectional view of a cylindrical battery cell according to one embodiment of the present disclosure.

[0073] Figure 4 This is a diagram showing the battery canister in a cylindrical battery cell according to one embodiment of the present disclosure.

[0074] Figure 5 This is a plan view of a current collector in a cylindrical battery cell according to one embodiment of the present disclosure.

[0075] Figure 6 yes Figure 5 A modified implementation of one side of the manifold.

[0076] Figure 7 yes Figure 5 A variant implementation on the other side of the manifold.

[0077] Figure 8 yes Figure 3A cross-sectional view of another embodiment of the cylindrical battery cell.

[0078] Figure 9 This is a plan view showing the structure of an electrode plate according to one embodiment of the present disclosure.

[0079] Figure 10 It shows the basis Figure 9 A diagram defining the width, height, and spacing of the segments.

[0080] Figure 11 This is a plan view showing the structure of an electrode plate according to another embodiment of the present disclosure.

[0081] Figure 12 It shows the basis Figure 11 A diagram defining the width, height, and spacing of the segments.

[0082] Figure 13 This is a cross-sectional view of an electrode assembly according to one embodiment of the present disclosure, cut along the Y-axis direction (winding axis direction).

[0083] Figure 14 This is a cross-sectional view of an electrode assembly according to another embodiment of the present disclosure, cut along the Y-axis direction (winding axis direction).

[0084] Figure 15 This is a diagram schematically illustrating the configuration of a battery pack according to one embodiment of the present disclosure.

[0085] Figure 16 It includes Figure 15 A picture of a vehicle with a battery pack. Detailed Implementation

[0086] Exemplary embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Before the description, it should be understood that the terms or words used in the specification and appended claims should not be construed as limited to their general and dictionary meanings, but should be interpreted according to their meanings and concepts corresponding to the technical aspects of the present disclosure, based on the principle that the inventors are allowed to define the terms appropriately to obtain the best interpretation.

[0087] Therefore, the embodiments described herein and the illustrations shown in the figures are merely exemplary implementations of this disclosure and are not intended to fully describe the technical aspects of this disclosure. It should be understood that various other equivalents and modifications may be made to this disclosure at the time of filing.

[0088] Furthermore, to aid in understanding this disclosure, the accompanying drawings may show some elements at exaggerated dimensions rather than actual dimensions. Additionally, similar reference numerals may be used for similar elements in different embodiments.

[0089] Figure 1 This is a perspective view of a cylindrical battery cell according to one embodiment of the present disclosure. Figure 2 It is shown Figure 1 A three-dimensional cross-sectional view of the central portion of a cylindrical battery cell. Figure 3 This is a cross-sectional view of a cylindrical battery cell according to one embodiment of the present disclosure. Figure 4 This is a diagram illustrating the battery canister in a cylindrical battery cell according to one embodiment of the present disclosure. Figure 5 This is a plan view of a current collector in a cylindrical battery cell according to one embodiment of the present disclosure. Figure 6 yes Figure 5 A modified implementation of one side of the manifold, Figure 7 yes Figure 5 A variant implementation on the other side of the manifold, and Figure 8 yes Figure 3 A cross-sectional view of another embodiment of the cylindrical battery cell.

[0090] A cylindrical battery cell 10 according to one embodiment of the present disclosure will be described with reference to the accompanying drawings.

[0091] Preferably, the cylindrical battery cell 10 can be, for example, a cylindrical battery cell 10 with an aspect ratio (a value obtained by dividing the diameter of the cylindrical battery cell by its height, i.e., defined as the ratio of diameter Φ to height H) greater than about 0.4.

[0092] Here, the shape factor refers to the value representing the diameter and height of the cylindrical battery cell 10. According to one embodiment of this disclosure, the cylindrical battery cell 10 can be, for example, a 46110 battery cell, a 48750 battery cell, a 48110 battery cell, a 48800 battery cell, or a 46800 battery cell. In the value representing the shape factor, the first two digits represent the diameter of the battery cell, the last two digits represent the height of the battery cell, and the last digit 0 indicates that the cross-section of the battery cell is circular. When the height of the battery cell exceeds 100 mm, since a 3-digit number is needed to represent the height of the battery cell, the last digit 0 can be omitted.

[0093] According to one embodiment of the present disclosure, the battery cell may be a cylindrical battery cell 10 having a cylindrical shape with a diameter of approximately 46 mm, a height of approximately 110 mm, and an aspect ratio of 0.418.

[0094] According to another embodiment, the battery cell can be a cylindrical battery cell 10 having a cylindrical shape with a diameter of approximately 48 mm, a height of approximately 75 mm, and an aspect ratio of 0.640.

[0095] According to another embodiment, the battery cell can be a cylindrical battery cell 10 having a cylindrical shape with a diameter of approximately 48 mm, a height of approximately 110 mm, and an aspect ratio of 0.436.

[0096] According to another embodiment, the battery cell can be a cylindrical battery cell 10 having a cylindrical shape with a diameter of approximately 48 mm, a height of approximately 80 mm, and an aspect ratio of 0.600.

[0097] According to another embodiment, the battery cell can be a cylindrical battery cell 10 having a cylindrical shape with a diameter of approximately 46 mm, a height of approximately 80 mm, and an aspect ratio of 0.575.

[0098] Battery cells with an aspect ratio of approximately 0.4 or less have been used. For example, 18650 and 21700 battery cells have been used. In the case of the 18650 battery cell, the diameter is approximately 18 mm, the height is approximately 65 mm, and the aspect ratio is 0.277. In the case of the 21700 battery cell, the diameter is approximately 21 mm, the height is approximately 70 mm, and the aspect ratio is 0.300.

[0099] refer to Figure 2 and Figure 3 According to one embodiment of the present disclosure, a cylindrical battery cell 10 includes an electrode assembly 100, a cylindrical battery canister 200, a current collector 300, and battery cell terminals 400.

[0100] The electrode assembly 100 is configured as a wound core type, having a structure in which a sheet-like first electrode plate and a second electrode plate and a diaphragm inserted therebetween are wound in one direction.

[0101] refer to Figure 3 The first electrode plate includes a first uncoated region 110, in which no active material layer is coated at the end of the long side. Furthermore, the second electrode plate may also include a second uncoated region 120, in which no active material layer is coated at the end of the long side. That is, at least one of the first and second electrode plates may include an uncoated region along the winding direction where no active material is coated at the end of the long side.

[0102] Here, the first uncoated region 110 is exposed to the outside of the diaphragm while forming multiple winding turns at the center of the electrode assembly 100, and itself serves as an electrode connector.

[0103] That is, the electrode assembly 100 is configured such that a sheet-like first electrode plate and a second electrode plate are wound in one direction, sandwiching a separator. The first electrode plate can have a positive or negative polarity, and the polarity of the second electrode plate is opposite to that of the first electrode plate. In other words, the first electrode plate can be a positive or negative electrode plate, and the second electrode plate can be a negative or positive electrode plate, having a polarity opposite to that of the first electrode plate. However, for ease of explanation, the following description will primarily focus on the case where the first electrode plate is a positive electrode plate and the second electrode plate is a negative electrode plate.

[0104] The first electrode plate may be coated with a first electrode active material on one or both surfaces. In addition, the first electrode plate includes a first uncoated region 110 in which the first electrode active material is not coated at its ends.

[0105] The second electrode plate is coated with a second electrode active material on one or both surfaces. In addition, the second electrode plate includes a second uncoated region 120 in which the second electrode active material is not coated at its ends.

[0106] Furthermore, the first uncoated area 110 of the first electrode plate and the second uncoated area 120 of the second electrode plate are disposed in opposite directions. The first uncoated area 110 extends toward the closure portion 210 of the battery can 200, and the second uncoated area 120 extends toward the opening portion 220 of the battery can 200.

[0107] In this disclosure, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate may be, but is not limited to, any type of active material well known in the relevant art.

[0108] In one embodiment, the positive electrode active material may include materials of formula A[A] x M y O 2+z The alkali metal compound represented (A includes at least one of Li, Na or K; M includes at least one selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr, Ru and Cr; x≥0, 1≤x+y≤2, -0.1≤z≤2; the stoichiometric coefficients x, y and z are chosen to maintain the electroneutrality of the compound).

[0109] In another embodiment, the positive electrode active material may be the alkali metal compound xLiM disclosed in US6677082 and US6680143. 1 O2-(1-x)Li2M 2 O3(M 1 Includes at least one element with an average trivalent oxidation state; M 2Includes at least one element with an average tetravalent oxidation state; 0 ≤ x ≤ 1).

[0110] In yet another embodiment, the positive electrode active material may be made of formula Li a M 1 x Fe 1-x M 2 y P 1-y M 3 z O 4-z Lithium metal phosphate (M) 1 Includes at least one selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Mg, and Al; M 2 Includes at least one selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Mg, Al, As, Sb, Si, Ge, V, and S; M 3 Includes halogen elements that optionally include F; 0 < a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y < 1, 0 ≤ z < 1; the stoichiometric coefficients a, x, y and z are chosen to maintain the electroneutrality of the compound), or lithium metal phosphate represented by Li3M2(PO4)3 (M includes at least one selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Mg and Al).

[0111] Preferably, the positive electrode active material may include primary particles and / or secondary particles formed by the aggregation of primary particles.

[0112] In one embodiment, the negative electrode active material may include carbon materials, lithium metal or lithium metal compounds, silicon or silicon compounds, tin or tin compounds. Metal oxides with a potential less than 2V (such as TiO2 and SnO2) may be used as the negative electrode active material. Carbon materials may include low-crystalline carbon and high-crystalline carbon.

[0113] The diaphragm may include a porous polymer membrane, for example, a porous polymer membrane made of polyolefin-based polymers such as ethylene homopolymers, propylene homopolymers, ethylene / butene copolymers, ethylene / hexene copolymers, and ethylene / methacrylate copolymers, used alone or in combination thereof. In another embodiment, the diaphragm may include a common porous nonwoven fabric, such as a nonwoven fabric made of high-melting-point glass fibers and polyethylene terephthalate fibers.

[0114] The diaphragm may have a coating of inorganic particles on at least one surface. Alternatively, the diaphragm itself may also be a coating of inorganic particles. The particles forming the coating may be bonded together with an adhesive to create interstitial volumes between adjacent particles.

[0115] Inorganic particles may include inorganic particles having a dielectric constant of 5 or higher. Non-limiting embodiments of inorganic particles may include those selected from Pb(Zr,Ti)O3 (PZT), Pb... 1-x La x Zr 1-y Ti y O3(PLZT), PB(Mg3Nb) 2 / 3 At least one material from the group consisting of O3-PbTiO3 (PMN-PT), BaTiO3, hafnium dioxide (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.

[0116] Electrolytes can be those with properties such as A + B -- Salts of the structure. Here, A + Including alkali metal cations, such as Li + Na + K + Or a combination thereof. Furthermore, B - Including the choice of F - Cl-, Br-, I-, NO3 - N(CN) 2- BF 4- ,ClO 4- AlO 4- AlCl 4- PF 6- 、SbF 6- AsF 6- BF2C2O 4- BC4O 8- (CF3)2PF 4- (CF3)3PF3 - (CF3)4PF 2- , (CF3)5PF-, (CF3)6P-, CF3SO 3- C4F9SO 3- CF3CF2SO 3- , (CF3SO2)2N-, (FSO2)2N-, CF3CF2(CF3)2CO-, (CF3SO2)2CH-, (SF5)3C-, (CF3SO2)3C-, CF3(CF2)7SO 3- CF3CO 2- CH3CO2 - At least one anion from the group consisting of SCN- and (CF3CF2SO2)2N-.

[0117] Electrolytes can be used by dissolving them in organic solvents. Organic solvents may include at least one of propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), or γ-butyrolactone.

[0118] The battery canister 200 is cylindrical in shape, housing the electrode assembly 100 and electrically connected to the second electrode plate of the electrode assembly 100. Therefore, the battery canister 200 can have the same polarity as the second electrode plate. That is, when the second electrode plate has a negative polarity, the battery canister 200 also has a negative polarity.

[0119] When the size of the battery can 200 is set according to a preset standard, as the size of the electrode assembly 100 increases, the total capacity of the battery cell increases, but the gap between the battery can 200 and the electrode assembly 100 decreases.

[0120] That is, the gap between the battery can 200 and the electrode assembly 100 decreases as the size of the electrode assembly 100 increases, so as to increase the total capacity of the battery cell. In order to increase the capacity of the battery cell, the insulator 600 needs to be arranged in the reduced gap between the battery can 200 and the electrode assembly 100. For this reason, the thickness of the insulator 600 is preferably as small as possible.

[0121] refer to Figure 4 The battery canister 200 may have a closed portion 210 and an open portion 220 that are opposite to each other.

[0122] For example, based on Figure 4 The battery canister 200 may have an opening 220 at the bottom. The electrode assembly 100 is accommodated through the opening 220 at the bottom of the battery canister 200, and electrolyte is injected through the opening 220 at the bottom of the battery canister 200.

[0123] That is, the battery can 200 is a generally cylindrical container with an opening 220 at the bottom, and is made of, for example, a conductive material (such as metal). The battery can 200 may be made of conductive metals (e.g., aluminum, steel, and stainless steel), but is not limited thereto. A Ni coating layer may be formed on the surface of the battery can 200.

[0124] Furthermore, based on Figure 4 The battery canister 200 may have a closure 210 on its top. The closure 210 may have a through hole 211, and as shown... Figure 3 As shown, the battery cell terminal 400 can be connected to the through hole 211.

[0125] An insulator 600 is disposed between the upper end of the electrode assembly 100 and the inner surface of the battery canister 200, or between the current collector 300, which is connected to the upper part of the electrode assembly 100, and the inner surface of the closed portion 210 of the battery canister 200. (Reference) Figure 3 An insulator 600 can be inserted between the closure 210 and the current collector 300. The insulator 600 prevents the current collector 300 and the battery canister 200 from contacting each other. That is, the insulator 600 is housed within the battery canister 200 and configured to cover at least a portion of the electrode assembly 100, preventing electrical connection between the first uncoated area 110 and the battery canister 200, or between the current collector 300 and the battery canister 200. Alternatively, the insulator 600 can also be inserted between the upper end of the outer periphery of the electrode assembly 100 and the sidewall of the battery canister 200. That is, the insulator 600 can also be inserted between the first uncoated area 110 and the sidewall of the battery canister 200. Alternatively, as described below, an insulating tape 500 can be connected between the upper end of the outer periphery of the electrode assembly 100 and the sidewall of the battery canister 200, instead of the insulator 600. Therefore, the insulator 600 can be made of a material with insulating properties. For example, the insulator 600 can be, but is not limited to, insulating polymer materials. For example, insulator 600 can be made of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polypropylene (PP).

[0126] The insulator 600, together with the insulating tape 500, prevents contact between the current collector 300 and the battery can 200, and between the side surface of the first uncoated area 110 and the battery can 200. Specifically, the insulator 600 prevents contact between the current collector 300 and the battery can 200, and the insulating tape 500 prevents contact between the side surface of the electrode assembly 100 (i.e., the side surface of the first uncoated area 110) and the battery can 200. Without the current collector 300, the insulator 600 prevents contact between the upper side of the first uncoated area 110 and the battery can 200.

[0127] The insulator 600 may include, for example, an elastic material. Therefore, when vibration or external impact is applied to the cylindrical battery cell 10, the insulator 600 can absorb these impacts as it elastically returns to its original state after compression. Thus, when vibration or external impact is applied to the battery cell, damage to the internal components of the battery cell can be minimized.

[0128] The insulator 600 may have a central hole with a predetermined diameter. For example, the insulator 600 may have a generally circular central hole adjacent to the winding center. Due to the presence of the central hole, the battery cell terminal 400 can contact the current collector 300 or the first uncoated area 110. The terminal insertion portion 410 of the battery cell terminal 400 passes through the central hole formed in the insulator 600 and connects to the current collector 300 or the first uncoated area 110. The central hole formed in the insulator 600 may be formed at a position corresponding to the hole formed at the winding center of the electrode assembly 100.

[0129] Meanwhile, when the weld between the battery cell terminal 400 and the terminal connection portion 330 of the current collector 300 is located inside the hole formed at the winding center of the electrode assembly 100, there is a risk of damaging the electrode assembly 100. To prevent this, the flat portion formed at the lower end of the battery cell terminal 400 that connects to the terminal connection portion 330 can be located at the same height as the lower surface of the insulator 600 or at a higher height. In this case, the weld between the battery cell terminal 400 and the current collector 300 is located outside the hole formed at the winding center of the electrode assembly 100.

[0130] With this in mind, the thickness of the insulator 600 can be equal to or greater than the distance from the inner surface of the closure portion 210 of the battery can 200 to the flat portion located at the lower end of the battery cell terminal 400. Simultaneously, the insulator 600 can have a thickness corresponding to the distance between the inner surface of the closure portion 210 of the battery can 200 and the current collector 300, to fill the space along the height direction between the inner surface of the closure portion 210 of the battery can 200 and the current collector 300, thereby preventing the creation of space that would allow the electrode assembly 100 to move vertically.

[0131] In another aspect, the upper surface of the insulator 600 can contact the inner surface of the closure portion 210 of the battery can 200, and the lower surface of the insulator 600 can contact the upper surface of the current collector 300.

[0132] The battery can 200 may include a rolled edge portion 240 and a crimped portion 250 located at the lower part. The rolled edge portion 240 is formed by rolling the outer periphery of the outer peripheral surface of the battery can 200 inward in the region adjacent to the opening 220 of the battery can 200.

[0133] The rolled edge 240 supports the electrode assembly 100 to prevent the electrode assembly 100, which has a size approximately corresponding to the width of the battery can 200, from sliding out of the opening 220 formed on the bottom of the battery can 200, and serves as a support for the cap plate 230. Furthermore, the rolled edge 240 supports the outer peripheral surface of the sealing gasket 260. The rolled edge 240 may be asymmetrical with respect to an imaginary plane passing through its innermost point. This asymmetrical shape is achieved during the sizing process of the battery can 200. The sizing process is a process that adjusts the height of the battery to the required profile by compressing the battery can 200 in the vertical direction.

[0134] The crimping portion 250 extends and bends to the inside of the battery can 200 to secure the cap plate 230 together with the sealing gasket 260 around the edge of the cap plate 230. Here, the crimping portion 250 is formed at the lower part of the battery can 200 based on the placement of the battery can 200. For example, when the battery can 200 is positioned as follows... Figure 3 The positioning shown so that the battery cell terminal 400 is arranged on the upper part, the crimping part 250 is based on Figure 3 It is formed at the lower part of the battery canister 200. Furthermore, as... Figure 3 As shown, the crimping portion 250 is formed below the rolled edge portion 240.

[0135] However, this disclosure does not exclude battery cans 200 that do not include at least one of the rolled edge portion 240 or the crimped portion 250. In this disclosure, when the battery can 200 does not include at least one of the rolled edge portion 240 or the crimped portion 250, the fixing of the electrode assembly 100, the fixing of the cap plate 230, or the sealing of the battery can 200 can be accomplished by additionally applying a component as a stop member for the electrode assembly 100, additionally applying a structure for mounting the cap plate 230, or welding between the battery can 200 and the cap plate 230.

[0136] based on Figure 3 A crimping portion 250 is formed below the rolled edge portion 240. The crimping portion 250 extends and bends around the edge of the cap plate 230 disposed below the rolled edge portion 240. The cap plate 230 is secured above the rolled edge portion 240 by means of the bent shape of the crimping portion 250. The crimping portion 250 may be omitted, and any other fixing structure may be used to secure the cap plate 230 covering the opening of the battery can 200. For example, the applicant's patent publication KR10-2019-0030016A discloses a cylindrical battery cell in which the rolled edge portion is omitted; such a structure may be used in this disclosure.

[0137] The current collector 300 is electrically connected to the first electrode plate on the electrode assembly 100. That is, the current collector 300 electrically connects the battery cell terminal 400 on the closed portion 210 of the battery canister 200 of the cylindrical battery cell 10 to the electrode assembly 100.

[0138] refer to Figure 5 The current collector 300 has a fuse portion 350 that is cut off when an overcurrent flows through it. The fuse portion 350 is formed on the connection portion 340 and is configured to have a greater resistance than other areas under the same current conditions. The minimum width of the fuse portion can be from 0.5 mm to 4.0 mm.

[0139] The current collector 300 is made of conductive metal and is connected to the first uncoated area 110 of the electrode assembly 100.

[0140] The current collector 300 is connected to a connection surface formed by bending the end of the first uncoated region 110 in a direction parallel to the current collector 300. The bending direction of the first uncoated region 110 may be, for example, toward the winding center of the electrode assembly 100.

[0141] When the first uncoated region 110 has the bent shape described above, the space occupied by the first uncoated region 110 is reduced, thereby increasing the energy density. In addition, the increased connection area between the first uncoated region 110 and the current collector 300 can improve the connection strength and reduce the resistance.

[0142] refer to Figure 5 The current collector 300 may include a frame portion 310, an uncoated area connection portion 320, a terminal connection portion 330, and a connection portion 340.

[0143] The frame portion 310 is arranged on the upper part of the electrode assembly and may have a generally frame shape forming an internal space S. Figure 5 The illustration shows a case where the border portion 310 has a generally circular border shape, but the shape of the border portion 310 is not limited to this. The border portion 310 may have a generally rectangular border shape, a hexagonal border shape, an octagonal border shape, or other shapes, different from those shown. The uncoated area connecting portion 320 and the terminal connecting portion 330 may be formed within the internal space S of the border portion 310. Furthermore, the uncoated area connecting portion 320 and the terminal connecting portion 330 may be electrically connected via the border portion 310 and the connecting portion 340. Here, the terminal connecting portion 330 may be located at the center of the internal space S of the border portion 310.

[0144] The uncoated area connection portion 320 extends inward from the frame portion 310 and is connected to the first uncoated area 110 of the electrode assembly 100. The uncoated area connection portion 320 can be connected to the first uncoated area 110 in various ways, for example, by welding (such as laser welding, ultrasonic welding or spot welding).

[0145] Multiple uncoated area connection portions 320 can be provided. These multiple uncoated area connection portions 320 can be arranged at different intervals along the extending direction of the frame portion 310, and preferably at the same interval. The extending lengths of the multiple uncoated area connection portions 320 can be the same, but are not limited thereto. In this case, the multiple uncoated area connection portions 320 can be configured to surround the terminal connection portion 330.

[0146] The terminal connection portion 330 is spaced apart from the uncoated area connection portion 320 by a certain space and is located inside the frame portion 310. The terminal connection portion 330 can be connected to the battery cell terminal 400, which will be explained later, by welding. Here, the terminal connection portion 330 can be located, for example, at the center of the internal space S of the frame portion 310. Furthermore, the terminal connection portion 330 can be arranged at a position corresponding to the hole formed at the winding center of the electrode assembly 100. The diameter of the terminal connection portion 330 can be 100% to 110% of the diameter of the hollow portion existing in the core of the electrode assembly 100.

[0147] The uncoated area connection portion 320 and the terminal connection portion 330 are not directly connected, but are spaced apart from each other and electrically connected by means of the frame portion 310. Therefore, the current collector 300 according to one embodiment of this disclosure has a structure in which the uncoated area connection portion 320 and the terminal connection portion 330 are not directly connected to each other but are connected by means of the frame portion 310, so that when an impact and / or vibration occurs at the cylindrical battery cell 10, the impact applied to the connection portion between the uncoated area connection portion 320 and the first uncoated area, and the connection portion between the terminal connection portion 330 and the battery cell terminal 400, can be dispersed. Therefore, the current collector 300 of this disclosure can minimize or prevent damage to the welded portion caused by external impacts.

[0148] That is, the manifold 300 has a structure in which stress can be concentrated at the connection between the frame portion 310 and the terminal connection portion 330 when an external impact is applied. However, no weld portion for connecting components is formed in this connection portion, which can prevent product defects caused by damage to the weld portion due to external impact.

[0149] The connecting portion 340 extends inward from the frame portion 310 and connects to the terminal connecting portion 330. The connecting portion 340 may be located between a pair of adjacent uncoated area connecting portions 320. In this case, in the extending direction of the frame portion 310, the distance from the connecting portion 340 to either of the pair of uncoated area connecting portions 320 may be equal to the distance from the connecting portion 340 to the other of the pair of uncoated area connecting portions 320 in the extending direction of the frame portion 310.

[0150] Furthermore, although not shown in the figure, multiple connecting portions 340 can be provided. Each of the multiple connecting portions 340 can be arranged between a pair of adjacent uncoated area connecting portions 320. The multiple connecting portions 340 can be arranged at equal intervals along the extending direction of the border portion 310.

[0151] Here, when multiple uncoated area connection portions 320 and / or connection portions 340 are provided, if the distance between the uncoated area connection portions 320 and / or the distance between the connection portions 340 and / or the distance between the uncoated area connection portions 320 and the connection portions 340 are uniformly formed, current can be smoothly generated from the uncoated area connection portions 320 toward the connection portions 340 or from the connection portions 340 toward the uncoated area connection portions 320.

[0152] At least a portion of the width of the connecting portion 340 may be smaller than the width of the uncoated connecting portion 320, and a fusible portion 350 may be formed on one side of the connecting portion 340. When the width of the connecting portion is smaller than the width of the uncoated connecting portion 320, the resistance in the connecting portion 340 increases. Therefore, when an overcurrent flows through the connecting portion 340, the resistance increases compared to other portions, and the heat increases. Here, since the fusible portion 350 is formed in the connecting portion 340, when an overcurrent occurs and the heat in the connecting portion 340 increases, the fusible portion 350 breaks to stop the flow of the overcurrent.

[0153] refer to Figure 5 The fusible portion 350 can be at least one notch 351 formed in the connecting portion 340. Since resistance is inversely proportional to area, if the notch 351 is formed in the connecting portion 340 such that the area in the region where the notch 351 is formed is reduced, the resistance in that region increases. Therefore, when an overcurrent flows, the heat in the notch 351 increases, leading to breakage. Here, the notch 351 can be formed at both ends of the connecting portion 340 in the width direction, on the upper surface of the connecting portion 340, or on the lower surface of the connecting portion 340. Preferably, the notch 351 can be recessed toward the interior of the connecting portion 340 in a direction that gradually or continuously reduces the width or thickness of the connecting portion 340. Alternatively, the notch 351 can be formed in the thickness direction of the connecting portion 340, rather than on a plane.

[0154] As another implementation, refer to Figure 6 The fusible portion 350 may be at least one through hole 352 formed in the connecting portion 340. The maximum width of the through hole 352 may be from 0.2 mm to 6 mm. Detailed operation of the through hole 352 is related to... Figure 5 The operations are common, so they will not be described in detail.

[0155] refer to Figure 7As another embodiment, the strip 353 can be connected to the fusible portion 350. If the strip 353 is connected to the fusible portion 350 of the connecting portion 340, when heat is generated in the connecting portion 340, the strip 353 will interrupt heat dissipation, thus preventing heat from being released, and therefore the heat reaches a higher level at the portion where the strip 353 is attached. Furthermore, breakage occurs due to the increased heat at the portion where the strip 353 is attached. Here, the strip 353 can be made of various materials, for example, it can be made of polyimide (PI) which is not easily deformed by heat, but the material is not limited to this.

[0156] As described later, at least a portion of the first uncoated region 110 of the electrode assembly 100 can be divided into a plurality of segments 61, 61', and at least a portion of the plurality of segments 61, 61' can be bent along a predetermined direction. Furthermore, when the plurality of segments 61, 61' are bent, they can be configured to overlap in multiple layers. This allows other segments of the plurality of segments 61, 61' to remain unbent; that is, some of the plurality of segments 61, 61' can be bent, while others can maintain their protruding shape along the winding axis without bending. Alternatively, the remaining unbent segments of the plurality of segments 61, 61' (i.e., the portions maintaining their protruding shape along the winding axis) can be cut.

[0157] When multiple segments 61, 61' are bent and overlapped in multiple layers, no gaps are formed between the overlapping segments 61, 61'. Therefore, foreign matter generated when the fuse portion 350 of the current collector 300 is cut by overcurrent will not flow into the wound-core electrode assembly 100. However, if a portion of the multiple segments 61, 61' has an unbent shape that remains unbent, or if the unbent portions of the multiple segments 61, 61' are cut, gaps are formed in this region between the multiple segments 61, 61'. As a result, foreign matter generated when the fuse portion 350 is cut may be introduced into the wound-core electrode assembly 100. If foreign matter flows into the wound-core electrode assembly 100, the diaphragm may be damaged by the foreign matter, or an internal short circuit may occur due to the foreign matter.

[0158] According to one embodiment of the present disclosure, the cylindrical battery cell 10 solves the above problems by appropriately adjusting the position of the fuse portion 350 formed in the connecting portion 340. For example, the fuse portion 350 is configured to be located above the bent sections 61, 61' of the plurality of sections 61, 61', away from the unbent sections or cut sections of the plurality of sections 61, 61'. Accordingly, even when the fuse portion 350 is cut to generate foreign matter, the foreign matter will fall on the upper side of the bent sections of the plurality of sections 61, 61' as described above. Therefore, if the plurality of sections 61, 61' are bent and overlapped in multiple layers, no gaps will be formed between the plurality of sections 61, 61', and therefore foreign matter will not flow into the wound electrode assembly 100. Therefore, there is an effect of preventing foreign matter from damaging the separator and / or causing internal short circuits. Preferably, the fusible portion 350 can be formed on the connecting portion 340 at a distance of 40% to 90% of the maximum radius of the electrode assembly 100 from the center of the electrode assembly 100.

[0159] The current collector 300 can be connected to the terminal insertion portion 410 of the battery cell terminal 400. That is, at least a portion of the bottom surface of the terminal insertion portion 410 of the battery cell terminal 400 can be formed with a flat portion parallel to the inner surface of the closing portion 210 of the battery canister 200, and the current collector 300 can be connected to the flat portion of the battery cell terminal 400.

[0160] Electrode assembly 100 may include a welding target region in which the number of overlapping layers in segments of the first uncoated region 110 is kept constant along the radial direction of electrode assembly 100, and current collector 300 may be coupled to the first uncoated region 110 within the welding target region. In this region, since the number of overlapping layers is kept to a maximum, it may be advantageous for current collector 300 and the first uncoated region 110, as explained later, to be welded within this region. This is to prevent the laser beam from penetrating the first uncoated region 110 and damaging electrode assembly 100 when, for example, laser welding is applied, the laser output is increased to improve weld quality. Furthermore, this is also to effectively prevent foreign matter such as welding spatter from entering electrode assembly 100.

[0161] The electrical connection portion of the terminal insertion portion 410 may have, for example, a generally cylindrical shape. Of course, the shape of the electrical connection portion of the terminal insertion portion 410 is not limited to this. The electrical connection portion of the terminal insertion portion 410 may have various shapes, such as a cylindrical shape with an elliptical cross-section, a square column shape, a hexagonal column shape, or an octagonal column shape. The bottom surface of the electrical connection portion of the terminal insertion portion 410 may be formed to be at least partially generally flat.

[0162] The bottom surface of the central region of the terminal insertion portion 410 and the current collector 300 can be joined by, for example, laser welding, spot welding, or ultrasonic welding. Welding can be performed by irradiating a laser through a hole formed in the winding center of the electrode assembly 100 or by inserting an ultrasonic welding or spot welding tool to form a weld bead on one surface of the current collector 300 (the surface facing the hole formed in the winding center of the electrode assembly 100). A guide tube (not shown) for welding can be inserted into the hole formed in the winding center. When welding is performed with the guide tube inserted, the risk of damaging the diaphragm (which forms the inner wall of the hole formed in the winding center) can be reduced.

[0163] The solder pattern drawn by solder beads formed on one surface of the terminal connection portion 330 of the current collector 300 can be drawn around the center of the bottom surface of the electrical connection portion of the terminal insertion portion 410. This solder pattern can be, for example, generally circular, and alternatively, can have a generally elliptical or polygonal shape (e.g., a generally square, hexagonal, octagonal, etc.). The solder pattern formed by the solder beads can be formed continuously or discontinuously. The shapes of circles, ellipses, polygons, etc. (examples of the shapes of solder patterns formed by solder beads) do not refer to geometrically perfect circles, ellipses, polygons, etc.

[0164] Simultaneously, the diameter of the flat portion formed on the bottom surface of the electrical connection portion of the terminal insertion portion 410 can be determined taking into account the welding strength with the current collector 300. The tensile force of the weld between the flat portion and the current collector 300 can be at least about 2 kgf or more, 5 kgf or more, 6 kgf or more, 7 kgf or more, 8 kgf or more, 9 kgf or more, or 10 kgf or more. It is desirable to maximize the tensile force of the weld within the allowable range by selecting the optimal welding method.

[0165] To meet the tensile strength requirements of the weld, the diameter (or maximum width) of the weld pattern formed on the flat portion can be at least approximately 2 mm. When the area S of the weld bead appearing on the surface of the weld zone is converted to the area of ​​a circle (πr... 2 When ), the diameter of the welded pattern can be defined as the conversion diameter of the corresponding circle (2*(S / π)). 0.5 ).

[0166] The flat portion formed on the bottom surface of the electrical connection portion of the terminal insertion portion 410 corresponds to the solderable area. The diameter of the solderable area can be approximately 3 mm to 14 mm. If the diameter of the solderable area is less than approximately 3 mm, it is difficult to guarantee a weld pattern with a diameter (conversion diameter) of 2 mm or more. In particular, when using laser welding to form the weld pattern, it is difficult to guarantee a weld pattern with a diameter of 2 mm or more due to laser beam interference. If the diameter of the solderable area is approximately greater than 14 mm, the diameter of the exposed portion of the battery cell terminal 400 will inevitably increase further, making it difficult to guarantee that the outer surface of the battery can 200 has sufficient area to be used as an electrode terminal with the opposite polarity to the battery cell terminal 400.

[0167] Considering the diameter conditions of the weld pattern and the weldable zone, it is preferable that the ratio of the area of ​​the weld pattern to the area of ​​the weldable zone required to ensure a tensile strength of at least approximately 2 kgf in the weld is approximately 2.04% (π1). 2 / π7 2 ) to 44.4% (π1 2 / π1.5 2 ).

[0168] In one embodiment, when the flat portion formed on the bottom surface of the electrical connection portion of the terminal insertion portion 410 and the current collector 300 are laser welded and the weld beads are welded with continuous or discontinuous lines drawn in the form of a generally arcuate pattern, the diameter of the arcuate weld pattern is preferably about 2 mm or more, and preferably about 4 mm or more. When the diameter of the arcuate weld pattern meets the corresponding condition, sufficient weld strength can be ensured by increasing the tensile force of the weld portion to about 2 kgf or more.

[0169] In another embodiment, when the flat portion formed on the bottom surface of the electrical connection portion of the terminal insertion portion 410 is ultrasonically welded to the current collector 300 to form a circular pattern, the diameter of the circular weld pattern is preferably about 2 mm or more. When the diameter of the circular weld pattern meets the corresponding condition, sufficient weld strength can be ensured by increasing the tensile force of the weld portion to about 2 kgf or more.

[0170] The diameter of the flat portion corresponding to the weldable area formed on the bottom surface of the battery cell terminal 400 can be adjusted within a range of approximately 3mm to 14mm. If the radius of the flat portion is less than approximately 3mm, it is difficult to form a weld pattern with a diameter of approximately 2mm or more using laser welding tools, ultrasonic welding tools, etc.

[0171] Meanwhile, the cylindrical battery cell 10 according to one embodiment of the present disclosure has a structure as described above, in which the bottom surface of the electrical connection portion of the terminal insertion portion 410 is welded and connected to the current collector 300, thus maximizing the connection area between the current collector 300 and the battery cell terminal 400. That is, at least a portion of the bottom surface of the electrical connection portion is formed to be flat, thereby maximizing the connection area between the battery cell terminal 400 and the current collector 300. Therefore, the cylindrical battery cell 10 according to one embodiment of the present disclosure can ensure smooth current flow at the connection portion between the current collector 300 and the battery cell terminal 400 even when there is a large current flow due to fast charging, thereby reducing charging time and reducing the generated heat.

[0172] The current collector 300 is connected to the upper portion of the electrode assembly 100. Furthermore, the current collector 300 is also connected to the battery cell terminal 400. That is, the current collector 300 connects the first uncoated area 110 of the electrode assembly 100 and the battery cell terminal 400 as needed. The current collector 300 is made of a conductive metal material and is connected to the first uncoated area 110. Although not shown in the figures, the current collector 300 may include a plurality of irregular portions radially formed on its lower surface. After the irregular portions are formed, they can be press-fitted into the first uncoated area 110 by pressing the current collector 300.

[0173] At least a portion of the bottom surface of the battery cell terminal 400 (i.e., the bottom surface of the electrical connection portion of the terminal insertion portion 410) may be formed with a flat portion that is substantially parallel to the inner surface of the closure portion 210 of the battery can 200, and the current collector 300 is connected to the flat portion.

[0174] The manifold 300 is connected to the end of the first uncoated region 110. The first uncoated region 110 and the manifold 300 can be joined, for example, by laser welding. Laser welding can be performed by partially melting the base material of the manifold 300, or by inserting solder between the manifold 300 and the first uncoated region 110. In this case, the solder preferably has a lower melting point than the manifold 300 and the first uncoated region 110.

[0175] The current collector 300 can be connected to a connection surface formed by bending the end of the first uncoated region 110 in a direction parallel to the current collector 300. The bending direction of the first uncoated region 110 can be, for example, toward the winding center (i.e., the core) of the electrode assembly 100. When the first uncoated region 110 has such a bending shape, the space occupied by the first uncoated region 110 can be reduced, thereby increasing the energy density. Furthermore, since the connection area between the first uncoated region 110 and the current collector 300 is increased, it can result in improved connection strength and reduced resistance.

[0176] The battery cell terminal 400 is made of conductive metal and is connected to a through hole 211 formed in the closure portion 210 of the battery can 200 and electrically connected to the current collector 300. Furthermore, the battery cell terminal 400 is electrically connected to the first electrode plate of the electrode assembly 100 via the current collector 300, and therefore has positive polarity. That is, the battery cell terminal 400 can serve as either the first electrode terminal or the positive terminal. Additionally, as described above, the battery can 200 is electrically connected to the second electrode plate of the electrode assembly 100, and therefore has negative polarity.

[0177] The battery cell terminal 400 may include a terminal insertion portion 410. The terminal insertion portion 410 may be inserted into the battery can 200 through a through hole 211 formed in the closure portion 210 of the battery can 200, thereby electrically connecting the lower end to the first uncoated area 110.

[0178] The terminal insertion part 410 can be connected to the current collector 300 or the first uncoated area 110 via both the battery can 200 and the insulator 600. The terminal insertion part 410 can be fixed to the through hole 211 by riveting the inner surface facing the upper end of the battery can 200, and its lower edge is pressed by a slit clamp.

[0179] That is, the lower outer periphery of the terminal insertion portion 410 can be bent toward the inner surface of the battery can 200 by applying a slit clamp. For this purpose, the maximum width of the end of the terminal insertion portion 410 can be greater than the maximum width of the hole formed in the battery can 200 for the terminal insertion portion 410 to pass through.

[0180] Meanwhile, in another embodiment, the terminal insertion portion 410 may not be bent toward the inner surface of the battery can 200. For example, see reference... Figure 8 The terminal insertion portion 410 may have a generally cylindrical shape with a hole passing through approximately the center of the upper surface of the battery can 200.

[0181] In one embodiment of this disclosure, the terminal insertion portion 410 may have a circular shape in a plane, but is not limited thereto. The terminal insertion portion 410 may optionally have a polygonal shape, a star shape, or a shape with legs extending from the center.

[0182] The terminal insertion portion 410 of the battery cell terminal 400 can pass through the central hole of the insulator 600. Furthermore, the diameter of the central hole of the insulator 600 can be equal to or greater than the diameter of the terminal insertion portion 410. Additionally, the terminal insertion portion 410 of the battery cell terminal 400 can pass through the central hole of the insulator 600 and be electrically connected to the current collector 300.

[0183] refer to Figure 3 The cap plate 230 is configured to close the opening 220 of the battery canister 200. The cap plate 230 may be made of, for example, metal to ensure rigidity.

[0184] The cap plate 230 closes the opening 220 on the bottom of the battery canister 200. The cap plate 230 can be separate from the electrode assembly 100 and can be non-polar. That is, even if the cap plate 230 is made of conductive metal, it can still be non-polar. A non-polar cap plate 230 means that the cap plate 230 is electrically insulated from the battery canister 200 and the battery cell terminals 400. The cap plate 230 can be polar or non-polar, and its material is not necessarily limited to conductive metal.

[0185] The cap plate 230 can be mounted and supported on the rolled edge 240 of the battery can 200. Furthermore, the cap plate 230 is secured by the crimping portion 250. A sealing gasket 260 can be inserted between the cap plate 230 and the crimping portion 250 of the battery can 200 to ensure the sealing of the battery can 200. That is, the sealing gasket 260 can be inserted between the edge of the cap plate 230 and the opening 220 of the battery can 200.

[0186] Meanwhile, the battery can 200 of this disclosure may not include at least one of the rolled edge portion 240 or the crimped portion 250. In this case, the sealing gasket 260 may be inserted between the cap plate 230 and the fixing structure provided at the opening 220 of the battery can 200 to ensure the sealing of the battery can 200.

[0187] The cap plate 230 may include a venting notch 231 that breaks when the internal pressure of the battery can 200 exceeds a threshold.

[0188] For example, the vent notch 231 can be formed on both surfaces of the cap plate 230, and at least one of a continuous circular pattern, a discontinuous circular pattern, or a linear pattern can be formed on the surface of the cap plate 230. Furthermore, the vent notch 231 can be formed into various different patterns.

[0189] A vent 231 can be formed on the bottom of the battery can 200 based on the placement of the battery can 200. When the vent 231 breaks, the gas in the battery can 200 can be discharged through the bottom of the battery can 200.

[0190] For example, when the battery can 200 is positioned such that the battery cell terminals 400 are arranged at the top (e.g.) Figure 3 As shown in the diagram, the vent notch 231 can be based on Figure 3 It is formed on the bottom of the battery canister 200.

[0191] The venting notch 231 can be a region with a thickness smaller than any other region of the cap plate 230.

[0192] Because the vent notch 231 is thinner than the surrounding area, it can break more easily than the surrounding area. When the internal pressure of the battery can 200 is equal to or higher than a predetermined level, the vent notch 231 can break to release the gas inside the battery can 200.

[0193] For example, the vent notch 231 can be formed by making cuts on one or both surfaces of the cap plate 230 to partially reduce the thickness of the battery canister 200.

[0194] According to one embodiment of the present disclosure, the cylindrical battery cell 10 may have a structure in which the positive and negative terminals are arranged at the top, resulting in a more complex upper structure than a lower structure.

[0195] Therefore, in order to smoothly release the gas inside the battery canister 200, the cap plate 230 forming the lower surface of the cylindrical battery cell 10 may have a venting notch 231.

[0196] As described above, it is beneficial to user safety to release the gas inside the battery canister 200 located in the cylindrical battery cell 10 downwards. For example, if the cylindrical battery cell 10 is positioned below the driver's seat in an electric vehicle, there may be a risk of driver injury if the gas is released upwards.

[0197] However, when the gas is discharged through the bottom of the battery canister 200 as in the cylindrical battery cell 10 according to one embodiment of the present disclosure, the aforementioned problem does not occur when the cylindrical battery cell 10 is positioned directly below the driver's seat in the electric vehicle.

[0198] refer to Figure 3 The lower end of the cap plate 230 is preferably positioned higher than the lower end of the battery can 200. In this case, even when the lower end of the battery can 200 contacts the ground or the bottom of the housing used to form the module or battery pack, the cap plate 230 will not contact the ground or the bottom of the housing used to form the module or battery pack.

[0199] Therefore, it is possible to prevent the pressure required for the vent notch 231 to break due to the weight of the cylindrical battery cell 10 from being different from the design pressure, thereby ensuring that the vent notch 231 breaks smoothly.

[0200] refer to Figure 3 The lower current collector 700 is connected to the bottom of the electrode assembly 100. The lower current collector 700 is made of a conductive metal (e.g., aluminum, steel, copper, and nickel) and is electrically connected to the second uncoated area 120 of the second electrode plate.

[0201] Preferably, the lower manifold 700 is electrically connected to the battery canister 200. For this purpose, at least a portion of the edge region of the lower manifold 700 can be inserted and fixed between the inner surface of the battery canister 200 and the sealing gasket 260.

[0202] In one embodiment, at least a portion of the edge region of the lower current collector 700 can be welded to the rolled edge 240 and supported on the lower end surface of the rolled edge 240 formed at the lower end of the battery canister 200. In a variant, at least a portion of the edge region of the lower current collector 700 can be directly welded to the inner wall surface of the battery canister 200.

[0203] Preferably, at least a portion of the remaining area, excluding the connection area between the lower manifold 700 and the rolled edge, can be connected to the bent surface of the second uncoated area 120 by welding (e.g., laser welding).

[0204] For example, at least a portion of the edge of the lower manifold 700 may be electrically connected to the surface of the adjacent crimp portion 250 on the upper and lower surfaces of the rolled edge portion 240.

[0205] Meanwhile, the electrode assembly 100 according to one embodiment of the present disclosure may include a first electrode plate and a second electrode plate. The first electrode plate may include a first uncoated region 110, and the second electrode plate may include a second uncoated region 120. Furthermore, at least a portion of the first uncoated region 110 and / or the second uncoated region 120 may be divided into multiple segments, the structure of which will be described in detail below.

[0206] Figure 9 This is a plan view showing the structure of an electrode plate according to one embodiment of the present disclosure.

[0207] refer to Figure 9 In the uncoated area 43 of the electrode plate 60, the heights of the core-side uncoated area B1 and the outer peripheral-side uncoated area B3 are 0 or higher, and less than the height of the intermediate uncoated area B2. Furthermore, the heights of the core-side uncoated area B1 and the outer peripheral-side uncoated area B3 may be equal or different.

[0208] Preferably, at least a portion of the intermediate uncoated region B2 may include a plurality of segments 61. The height of the plurality of segments 61 may gradually increase from the core to the outer periphery.

[0209] Segment 61 can be formed by laser cutting. Segment 61 can be formed by known metal film cutting processes (e.g., ultrasonic cutting or punching).

[0210] exist Figure 9 In the middle, preferably at the lower end of the cutting line between section 61 and active material layer 42 ( Figure 10A predetermined gap (C4) is formed in the section 61 to prevent damage to the active material layer 42 and / or the insulating coating layer 44 when bending the uncoated area 43. This is because stress concentration occurs near the lower end of the cutting line when the uncoated area 43 is bent. The gap is preferably 0.2 mm to 4 mm. When the gap is adjusted to the appropriate range, stress damage to the active material layer 42 and / or the insulating coating layer 44 near the lower end of the cutting line when bending the uncoated area 43 can be prevented. In addition, the gap can prevent damage to the active material layer 42 and / or the insulating coating layer 44 caused by cleaning during the cutting of section 61. Preferably, at least a portion of the insulating coating layer 44 can be exposed via the diaphragm when the electrode plate 60 is wound. In this case, the insulating coating layer 44 can support the bending point when section 61 is bent.

[0211] Multiple segments 61 can form multiple segment groups from the core to the periphery. At least one of the width, height, or spacing of the segments in the same segment group can be substantially equal.

[0212] Figure 10 This is a diagram illustrating the definition of the width, height, and spacing of section 61 according to one embodiment of the present disclosure.

[0213] refer to Figure 10 The width C1, height C2, and spacing C3 of section 61 are designed to prevent tearing of the uncoated area 43 when bending it, and to sufficiently increase the number of overlapping layers of the uncoated area 43 to improve welding strength, while preventing abnormal deformation of the uncoated area 43. Abnormal deformation refers to irregular deformation that occurs when the uncoated area below the bending point no longer maintains linearity and collapses.

[0214] Preferably, the width C1 of segment 61 can be adjusted within the range of 1 mm to 8 mm. When C1 is less than 1 mm, there is no overlapping area or empty space (gap) sufficient to ensure the welding strength when segment 61 is bent toward the core. Conversely, when C1 is greater than 8 mm, the uncoated area 43 near the bending point may be stress-torn when segment 61 is bent.

[0215] Furthermore, the height of segment 61 can be adjusted within the range of 2mm to 10mm. When C2 is less than 2mm, there is no overlapping area or empty space (gap) sufficient to ensure the welding strength when segment 61 is bent toward the core. Conversely, when C2 is greater than 10mm, it is difficult to uniformly maintain the flatness of the uncoated area in the winding direction X while fabricating the electrode plate. That is, the height of the uncoated area increases, causing expansion. Additionally, the spacing C3 of segment 61 can be adjusted within the range of 0.05mm to 1mm. When C3 is less than 0.05mm, the uncoated area 43 near the bending point may be torn by stress when segment 61 is bent. Conversely, when C3 is greater than 1mm, there is no overlapping area or empty space (gap) sufficient to ensure the welding strength when segment 61 is bent toward the core.

[0216] refer to Figure 10 The cutout 62 is positioned between two adjacent segments 61 in the winding direction X. The cutout 62 corresponds to the space formed by removing the uncoated area 43. Preferably, the lower corner of the cutout 62 may have a rounded shape (see partially enlarged figure). The rounded shape can reduce the stress applied to the lower end of the cutout 62 when winding the electrode plate 60 and / or bending the segment 61.

[0217] See again Figure 9 The width d of the uncoated area B1 on the core side B1 Designed to meet the requirement that when the section 61 of the uncoated area B2 in the middle of the core is bent toward the core, the uncoated area B1 on the core side should not cover the hollow part of the electrode assembly core.

[0218] In one embodiment, the width d of the uncoated core-side region B1 B1 It can be increased proportionally to the bending length of segment 61 in group 1. The bending length corresponds to the length of segment 61 relative to the bending point ( Figure 10 The height of 63) in the middle. Reference Figure 10 C4 represents the lowest bendable point. The bend point can be appropriately set at or above the position indicated by C4. The bend length is the length from the bend point to the top of segment 61. Specifically, the bend point can be set at a predetermined point at the height C2 of segment 61 relative to C4. This predetermined point can be set to prevent stress occurring when segment 61 is bent from causing mechanical damage to the active material layer 42 or the insulating coating layer 44, and to ensure a sufficient number of overlapping layers in the radial direction when segment 61 is bent in the radial direction of the electrode assembly, thereby ensuring sufficient weld strength when the current collector is welded to the bend area of ​​segment 61.

[0219] In one specific embodiment, when the electrode plate 60 is used to fabricate an electrode assembly for a cylindrical battery cell with a profile factor of 46800, the width d of the uncoated area B1 on the core side is determined according to the diameter of the electrode assembly core. B1It can be set from 180mm to 350mm.

[0220] In one implementation, the width of each segment group can be designed to form the same winding turn for the electrode assembly.

[0221] Here, when the electrode plate 60 is wound, the number of winding turns can be measured based on the end of the uncoated area B1 on the core side.

[0222] In another variation, the width of each segment group can be designed to form at least one winding turn of the electrode assembly.

[0223] In another variation, the width and / or height and / or spacing of segments 61 in the same segment group may gradually and / or progressively and / or irregularly increase or decrease within that group.

[0224] Groups 1 to 8 are just one embodiment of the segment groups. The number of groups, the number of segments 61 in each group, and the width of the groups can preferably be adjusted so that the segments 61 overlap in multiple layers to maximize stress dispersion and ensure sufficient weld strength during bending of the uncoated area 43.

[0225] In another variation, the height of the uncoated area B3 on the outer periphery can be gradually or progressively reduced.

[0226] In another variation, the segmented structure of the intermediate uncoated region B2 can extend to the outer peripheral uncoated region B3 (see dashed line). In this case, the outer peripheral uncoated region B3 can include multiple segments in the same manner as the intermediate uncoated region B2. In this case, the width and / or height and / or spacing of the segments of the outer peripheral uncoated region B3 can be greater than the width and / or height and / or spacing of the segments of the intermediate uncoated region B2. Optionally, the segmented structure of the outer peripheral uncoated region B3 can be the same as the outermost group of segments of the intermediate uncoated region B2.

[0227] In one specific embodiment, when the electrode plate 60 is used to fabricate the electrode assembly of a cylindrical battery cell with a profile factor of 46800, the width d of the uncoated area B1 on the core side is... B1The width can be from 180mm to 350mm. The width of Group 1 can be 35% to 40% of the width of the core-side uncoated area B1. The width of Group 2 can be 130% to 150% of the width of Group 1. The width of Group 3 can be 120% to 135% of the width of Group 2. The width of Group 4 can be 85% to 90% of the width of Group 3. The width of Group 5 can be 120% to 130% of the width of Group 4. The width of Group 6 can be 100% to 120% of the width of Group 5. The width of Group 7 can be 90% to 120% of the width of Group 6. The width of Group 8 can be 115% to 130% of the width of Group 7. In the same manner as the width of the core-side uncoated area B1, the width d of the peripheral uncoated area B3... B3 It can be 180mm to 350mm.

[0228] The widths of groups 1 through 8 do not show a uniform increasing or decreasing pattern because the width of the segments gradually increases from group 1 to group 8, but the number of segments in a group is limited to an integer. Therefore, the number of segments in a specific group may decrease. Thus, as shown, the width of the groups may show irregular variations from the core to the periphery.

[0229] That is, when the winding widths of three consecutive adjacent segments in the circumferential direction of the electrode assembly are W1, W2 and W3 respectively, it can include a combination of segments with W3 / W2 having smaller values ​​than W2 / W1.

[0230] In a specific embodiment, the situation is the same as that of groups 4 to 6. The width ratio of group 5 to group 4 is 120% to 130%, and the width ratio of groups 6 to group 5 is 100% to 120%, which is less than 120% to 130%.

[0231] Figure 11 This is a plan view showing the structure of an electrode plate according to another embodiment of the present disclosure, and Figure 12 It shows the basis Figure 11 A diagram defining the width, height, and spacing of the segments.

[0232] refer to Figure 11 Except for the shape of section 61' being changed from rectangular to trapezoidal, electrode plate 70 and Figure 9 They are basically the same.

[0233] Figure 12 The width, height, and spacing of the trapezoidal segment 61' are shown.

[0234] refer to Figure 12The width D1, height D2, and spacing D3 of section 61' are designed to prevent tearing of the uncoated area 43 near the bending point when bending the uncoated area 43, and to sufficiently increase the number of overlapping layers of the uncoated area 43 to ensure sufficient weld strength without abnormal deformation of the uncoated area 43.

[0235] Preferably, the width D1 of segment 61' can be adjusted within the range of 1 mm to 8 mm. When D1 is less than 1 mm, there is no overlapping area or empty space (gap) sufficient to ensure the welding strength when segment 61' is bent toward the core. Conversely, when D1 is greater than 8 mm, the uncoated area 43 near the bending point may be torn by stress when segment 61' is bent. Furthermore, the height of segment 61' can be adjusted within the range of 2 mm to 10 mm. When D2 is less than 2 mm, there is no overlapping area or empty space (gap) sufficient to ensure the welding strength when segment 61' is bent toward the core. Conversely, when D2 is greater than 10 mm, it is difficult to uniformly maintain the flatness of the uncoated area in the winding direction while fabricating the electrode plate. Furthermore, the spacing D3 of segment 61' can be adjusted within the range of 0.05 mm to 1 mm. When D3 is less than 0.05 mm, the uncoated area 43 near the bending point D4 may be torn by stress when segment 61' is bent. Conversely, when D3 is greater than 1 mm, there is no overlapping area or empty space (gap) sufficient to ensure the welding strength when section 61' is bent toward the core.

[0236] The cutout 62 is positioned between two adjacent segments 61' in the winding direction X. The cutout 62 corresponds to the space formed by removing the uncoated area 43. Preferably, the lower corner of the cutout 62 may have a rounded shape (see partially enlarged view). The rounded shape can reduce stress when bending the segment 61'.

[0237] refer to Figure 11 and Figure 12 In multiple sections 61', the inner base angle θ of the trapezoid increases from the core to the outer periphery. As the radius of the electrode plate 70 increases, the curvature also increases. When the inner base angle θ of section 61' increases with the radius of the electrode plate, the stress occurring in the radial and circumferential directions during bending of section 61' can be reduced. Furthermore, as the inner base angle θ increases, the overlap area and the number of overlapping layers with the inner section 61' increase during bending, thereby uniformly ensuring welding strength in both the radial and circumferential directions and forming a flat bending surface.

[0238] In one embodiment, when the electrode plate 70 is used to fabricate an electrode assembly for a cylindrical battery cell with a profile factor of 46800, the interior angle of segment 61' can be gradually increased from 60° to 85° as the radius of the electrode plate 70 increases from 4 mm to 22 mm.

[0239] In one variation, the height of the outer peripheral uncoated region B3 can gradually or progressively decrease in the same manner as in the first and second embodiments. Furthermore, the segmented structure of the intermediate uncoated region B2 can extend to the outer peripheral uncoated region B3 (see dashed lines). In this case, the outer peripheral uncoated region B3 can include multiple segments in the same manner as the intermediate uncoated region B2. In this case, the width and / or height and / or spacing of the segments of the outer peripheral uncoated region B3 can be greater than the width and / or height and / or spacing of the segments of the intermediate uncoated region B2. Optionally, the segmented structure of the outer peripheral uncoated region B3 can be substantially the same as the outermost group of segments of the intermediate uncoated region B2.

[0240] In one specific embodiment, when the electrode plate 70 is used to fabricate the electrode assembly of a cylindrical battery cell with a profile factor of 46800, the width d of the uncoated area B1 on the core side is... B1 The width can be from 180mm to 350mm. The width of Group 1 can be 35% to 40% of the width of the core-side uncoated area B1. The width of Group 2 can be 130% to 150% of the width of Group 1. The width of Group 3 can be 120% to 135% of the width of Group 2. The width of Group 4 can be 85% to 90% of the width of Group 3. The width of Group 5 can be 120% to 130% of the width of Group 4. The width of Group 6 can be 100% to 120% of the width of Group 5. The width of Group 7 can be 90% to 120% of the width of Group 6. The width of Group 8 can be 115% to 130% of the width of Group 7. In the same manner as the width of the core-side uncoated area B1, the width d of the peripheral uncoated area B3... B3 It can be 180mm to 350mm.

[0241] The widths of groups 1 through 8 do not show a uniform increasing or decreasing pattern because the width of the segments gradually increases from group 1 to group 8, but the number of segments in a group is limited to an integer. Therefore, the number of segments in a specific group may decrease. Thus, as shown, the width of the groups may show irregular variations from the core to the periphery.

[0242] That is, when the winding widths of three consecutive adjacent segments in the circumferential direction of the electrode assembly are W1, W2 and W3 respectively, it can include a combination of segments with W3 / W2 having smaller values ​​than W2 / W1.

[0243] In a specific embodiment, the situation is the same as that of groups 4 to 6. The width ratio of group 5 to group 4 is 120% to 130%, and the width ratio of groups 6 to group 5 is 100% to 120%, which is less than 120% to 130%.

[0244] Figure 13This is a cross-sectional view of an electrode assembly according to one embodiment of the present disclosure, cut along the Y-axis direction (winding axis direction).

[0245] refer to Figure 13 The uncoated area 43a of the electrode plate includes a core-side uncoated area B1 adjacent to the core of the electrode assembly 100, an outer peripheral-side uncoated area B3 adjacent to the outer peripheral surface of the electrode assembly 100, and an intermediate uncoated area B2 between the core-side uncoated area B1 and the outer peripheral-side uncoated area B3.

[0246] The height of the core-side uncoated region B1 is less than the height of the intermediate uncoated region B2. Furthermore, in the intermediate uncoated region B2, the bending length of the innermost uncoated region 43a is equal to or less than the radial length R of the core-side uncoated region B1. The bending length H corresponds to the height of the uncoated region 43a relative to its bending point. Figure 10 h in Figure 12 (h in the middle).

[0247] Therefore, even when the uncoated area B2 is bent, the hollow portion 102 of the core of the electrode assembly 100 is not closed by the bent portion. When the hollow portion 102 is not closed, the electrolyte injection process can be easily performed, thereby improving the electrolyte injection efficiency. In addition, by inserting a welding jig into the hollow portion 102, the welding process between the current collector of the negative electrode (or positive electrode) and the battery can (or rivet terminal) can be easily performed.

[0248] The height of the outer peripheral uncoated area B3 is less than the height of the middle uncoated area B2. Therefore, when the rolled edge of the battery can is pressed near the outer peripheral uncoated area B3, contact between the rolled edge and the outer peripheral uncoated area B3 can be prevented.

[0249] In one variant, with Figure 13 In contrast, the height of the uncoated area B3 on the outer periphery can gradually or progressively decrease. Furthermore, in Figure 13 In the middle, the height of the middle uncoated area B2 near the outer periphery is equal, but the height of the middle uncoated area B2 can gradually increase from the boundary between the core uncoated area B1 and the middle uncoated area B2 to the boundary between the middle uncoated area B2 and the outer periphery uncoated area B3.

[0250] The lower uncoated region 43b has the same structure as the upper uncoated region 43a. In a variant, the lower uncoated region 43b may have a conventional electrode plate structure or an electrode plate structure of other embodiments (variations).

[0251] The ends 101 of the upper uncoated region 43a and the lower uncoated region 43b can be bent from the outer periphery of the electrode assembly 100 toward the core. In this case, the core-side uncoated region B1 and the outer periphery-side uncoated region B3 are essentially not bent.

[0252] When the intermediate uncoated area B2 comprises multiple segments, bending stress can be reduced, thereby preventing tearing or abnormal deformation of the uncoated area 43a near the bending point. Furthermore, by adjusting the width and / or height and / or spacing of the segments according to the numerical range described in the above embodiments, when the segments bend towards the core, the segments overlap in sufficient multiple layers to ensure weld strength without forming voids (gaps) in the bending surface (the surface observed from the Y-axis).

[0253] Figure 14 This is a cross-sectional view of an electrode assembly according to another embodiment of the present disclosure, cut along the Y-axis direction (winding axis direction).

[0254] refer to Figure 14 Except that the height of the outermost uncoated area B3 is approximately equal to the height of the outermost part of the middle uncoated area B2, the electrode assembly 100' and Figure 13 The electrode assembly 100 is basically the same. The uncoated area B3 on the outer periphery can include multiple segments.

[0255] In electrode assembly 100', the height of the core-side uncoated region B1 is less than the height of the intermediate uncoated region B2. Furthermore, in the intermediate uncoated region B2, the bending length H of the innermost uncoated region is equal to or less than the radial length R of the core-side uncoated region B1.

[0256] Therefore, even when the uncoated area B2 is bent, the hollow portion 112 of the core of the electrode assembly 100' is not closed by the bent portion. When the hollow portion 112 is not closed, the electrolyte injection process can be easily performed, thereby improving the electrolyte injection efficiency. In addition, by inserting a welding jig into the hollow portion 112, the welding process between the current collector of the negative electrode (or positive electrode) and the battery can (or rivet terminal) can be easily performed.

[0257] In one variation, the height of the intermediate uncoated region B2 can gradually or progressively increase from the core to the outer periphery, extending to the outer peripheral uncoated region B3. In this case, the height of the uncoated region 43a can gradually or progressively increase from the boundary between the core-side uncoated region B1 and the intermediate uncoated region B2 to the outermost surface of the electrode assembly 100'.

[0258] The lower uncoated region 43b has the same structure as the upper uncoated region 43a. In a variant, the lower uncoated region 43b may have a conventional electrode plate structure or an electrode plate structure of other embodiments (variations).

[0259] The ends 111 of the upper uncoated region 43a and the lower uncoated region 43b can be bent from the outer periphery of the electrode assembly 100' toward the core. In this case, the core-side uncoated region B1 is essentially not bent.

[0260] When the intermediate uncoated area B2 and the outer peripheral uncoated area B3 comprise multiple segments, bending stress can be reduced, thereby preventing tearing or abnormal deformation of the uncoated areas 43a and 43b near the bending point. Furthermore, by adjusting the width and / or height and / or spacing of the segments according to the numerical range described in the above embodiment, when the segments bend towards the core, the segments overlap in sufficient multiple layers to ensure weld strength without forming voids (gaps) on the bending surface (the surface observed from the Y-axis).

[0261] Figure 15 This is a diagram schematically illustrating the configuration of a battery pack according to one embodiment of the present disclosure.

[0262] refer to Figure 15 According to one embodiment of the present disclosure, a battery pack 800 includes an assembly of cylindrical battery cells 10 electrically connected to each other and a battery pack housing 810 housing the assembly. The cylindrical battery cell 10 is the battery cell according to the above embodiment. In the figures, for ease of explanation, some components, such as busbars for electrical connections of the cylindrical battery cells 10, cooling units, external terminals, etc., are omitted.

[0263] The battery pack 800 can be installed in the vehicle 900. The vehicle 900 can be, for example, an electric vehicle, a hybrid electric vehicle, or a plug-in hybrid electric vehicle. The vehicle 900 includes four-wheeled vehicles or two-wheeled vehicles.

[0264] Figure 16 It shows including Figure 15 A picture of a vehicle with a battery pack.

[0265] refer to Figure 16 A vehicle 900 according to one embodiment of the present disclosure includes a battery pack 800 according to one embodiment of the present disclosure. The vehicle 900 operates using power supplied by the battery pack 800 according to one embodiment of the present disclosure.

[0266] This disclosure has been described in detail. However, it should be understood that while the detailed description and specific embodiments illustrate preferred embodiments of this disclosure, they are given by way of illustration only, as various variations and modifications within the scope of this disclosure will become apparent to those skilled in the art from this detailed description.

Claims

1. A cylindrical battery cell, comprising: a jelly-roll type electrode assembly having a structure in which first and second electrode plates each in a sheet shape sandwich a separator and are wound in one direction, the first electrode plate including first non-coated regions without an active material layer coated at end portions of long sides, the first non-coated regions being formed to expose to the outside of the separator and to serve as electrode tabs themselves with respect to a center of the electrode assembly by forming a plurality of winding turns; a battery can having an open portion accommodating the electrode assembly and a partially closed portion provided at opposite sides of the open portion, the battery can being electrically connected with the second electrode plate; a current collector plate electrically connected with the first non-coated regions of the first electrode plate and having a fuse portion to be cut off when overcurrent flows; and a battery cell terminal connected with the current collector plate through a through-hole of the closed portion of the battery can, wherein at least a portion of the first non-coated regions is divided into a plurality of segments in a winding direction of the electrode assembly, wherein at least a portion of the plurality of segments is bent in a radial direction of the electrode assembly, and wherein the fuse portion is positioned above a bent segment among the plurality of segments. 2.The cylindrical battery cell according to claim 1, wherein at least a portion of a bottom surface of the battery cell terminal is formed with a flat portion parallel to an inner surface of the closed portion of the battery can, and the current collector plate is coupled with the flat portion of the battery cell terminal. 3.The cylindrical battery cell according to claim 1, wherein the current collector plate is coupled on a coupling surface formed by bending end portions of the first non-coated regions. 4.The cylindrical battery cell according to claim 1, wherein the electrode assembly includes a welding target area in a radial direction of the electrode assembly, and wherein the current collector plate is coupled with the first non-coated regions within the welding target area. 5.The cylindrical battery cell according to claim 1, wherein the current collector plate includes: a bezel portion arranged at an upper portion of the electrode assembly; a non-coated region coupling portion configured to extend inward from the bezel portion and to be coupled with the first non-coated regions; a terminal coupling portion spaced apart from the non-coated region coupling portion and coupled with the battery cell terminal; and a connection portion configured to extend inward from the bezel portion to be connected with the terminal coupling portion and having the fuse portion, wherein the fuse portion has a greater resistance than other areas under the same current flow. 6.The cylindrical battery cell according to claim 5, wherein the bezel portion has a bezel shape in which at least a portion of an inner area is empty. 7.The cylindrical battery cell according to claim 5, wherein, the non-coated region coupling portion and the terminal coupling portion are electrically connected by means of the bezel portion. 8.The cylindrical battery cell according to claim 5, wherein the terminal coupling portion is located at a center of an inner space of the bezel portion. 9.The cylindrical battery cell according to claim 5, wherein A diameter of the terminal coupling portion is 100% to 110% of a diameter of a hollow portion present in a core of the electrode assembly.

10. The cylindrical battery cell of claim 5, wherein, The fuse portion is at least one notched groove formed in the connection portion.

11. The cylindrical battery cell of claim 10, wherein The notched groove is formed at an end portion in a width direction of the connection portion, at an upper surface of the connection portion, or at a lower surface of the connection portion.

12. The cylindrical battery cell of claim 11, wherein The notched groove is formed to be recessed toward an inside of the connection portion in a direction in which the width or the thickness of the connection portion is gradually or continuously reduced.

13. The cylindrical battery cell of claim 12, wherein A minimum width of the fuse portion is 0.5 mm to 4.0 mm.

14. The cylindrical battery cell of claim 5, wherein The fuse portion is at least one through hole formed in the connection portion.

15. The cylindrical battery cell of claim 14, wherein A maximum width of the through hole is 0.2 mm to 6 mm.

16. The cylindrical battery cell of claim 5, wherein The fuse portion is surrounded by a tape.

17. The cylindrical battery cell of claim 16, wherein The tape contains a polyimide (PI) material.

18. The cylindrical battery cell of claim 5, wherein The fuse portion is formed on the connection portion at a distance spaced apart from a center of the electrode assembly by 40% to 90% of a maximum radius of the electrode assembly.

19. The cylindrical battery cell of claim 1, wherein At least a portion of the plurality of segments is overlapped in a radial direction of the electrode assembly in a plurality of layers.

20. The cylindrical battery cell of claim 5, wherein, A welding pattern drawn by a weld bead formed on one surface of the terminal coupling portion of the current collector plate is drawn in a form surrounding a center of a bottom surface of the battery cell terminal.

21. The cylindrical battery cell of claim 20, wherein, The welding pattern is formed continuously or discontinuously.

22. The cylindrical battery cell of claim 5, wherein A tensile force of a welding portion formed between the terminal coupling portion of the current collector plate and a bottom surface of the battery cell terminal is 2 kgf or more.

23. The cylindrical battery cell of claim 20, wherein, A conversion diameter of the welding pattern drawn by the weld bead formed on one surface of the terminal coupling portion of the current collector plate is 2 mm or more.

24. The cylindrical battery cell of claim 1, further comprising: a cap plate configured to close the open portion of the battery can.

25. The cylindrical battery cell of claim 24, wherein, The cap plate is electrically separated from the electrode assembly and is non-polar.

26. The cylindrical battery cell of claim 24, wherein The closure portion has a through hole, and wherein the battery cell terminal is coupled with the through hole.

27. The cylindrical battery cell of claim 26, further comprising: An insulator interposed between the closed portion and the current collector plate.

28. The cylindrical battery cell of claim 27, wherein The insulator comprises an insulating polymer material.

29. The cylindrical battery cell of claim 27, wherein, The insulator is made of an elastic material.

30. The cylindrical battery cell of claim 27, wherein, The insulator has a central hole at the center, the central hole having a preset diameter.

31. The cylindrical battery cell of claim 27, wherein The thickness of the insulator corresponds to a distance between an inner surface of the closed portion of the battery can and the current collector plate.

32. The cylindrical battery cell of claim 27, wherein, An upper surface of the insulator is in contact with the inner surface of the closed portion of the battery can, and a lower surface of the insulator is in contact with an upper surface of the current collector plate.

33. The cylindrical battery cell of claim 30, wherein, The battery cell terminal comprises a terminal insertion portion, and wherein the terminal insertion portion is inserted into the battery can through the through-hole.

34. The cylindrical battery cell of claim 33, wherein The battery cell terminal is fixed to the through-hole while riveting a lower edge of the terminal insertion portion toward an inner surface of an upper end of the battery can.

35. The cylindrical battery cell of claim 33, wherein The diameter of the central hole of the insulator is equal to or greater than the diameter of the terminal insertion portion.

36. The cylindrical battery cell of claim 33, wherein, The terminal insertion portion of the battery cell terminal passes through the central hole of the insulator.

37. The cylindrical battery cell of claim 33, wherein The terminal insertion portion of the battery cell terminal is electrically coupled to the current collector plate through the central hole of the insulator.

38. The cylindrical battery cell of claim 24, further comprising: a sealing gasket between an edge of the cap plate and the open portion of the battery can, wherein the battery can includes a crimped portion that is press-fitted toward the inside of the battery can in a region adjacent to the open portion, and wherein the battery can includes a crimping portion that extends toward the inside of the battery can and is bent to surround the edge of the cap plate, and fixes the edge of the cap plate together with the sealing gasket.

39. The cylindrical battery cell of claim 38, wherein The crimping portion is formed in a lower portion of the battery can based on the placement of the battery can.

40. The cylindrical battery cell of claim 24, wherein The cap plate includes a venting notch configured to be broken when the internal pressure of the battery can is higher than a threshold value.

41. The cylindrical battery cell of claim 40, wherein The venting notch is formed on both surfaces of the cap plate, and forms at least one of a continuous circular pattern, a discontinuous circular pattern, and a linear pattern on the surface of the cap plate.

42. The cylindrical battery cell of claim 40, wherein The venting notch is formed on the bottom of the battery can based on the placement of the battery can, and when the venting notch is broken, gas in the battery can is discharged through the bottom of the battery can.

43. The cylindrical battery cell of claim 38, further comprising: a lower current collector plate coupled to a bottom of the electrode assembly.

44. The cylindrical battery cell of claim 43, wherein, at least a portion of an edge of the lower current collector plate is electrically coupled to the crimped portion, and at least a portion of a remaining area of the lower current collector plate other than the edge is electrically connected to a second non-coated area of the second electrode plate.

45. The cylindrical battery cell of claim 44, wherein, at least a portion of the edge of the lower current collector plate is electrically coupled to a surface of the upper surface and the lower surface of the crimped portion adjacent to the crimped portion.

46. The cylindrical battery cell of claim 45, wherein, the lower current collector plate and the crimped portion are laser-welded.

47. A battery pack comprising at least one cylindrical battery cell according to any one of claims 1 to 46.

48. A vehicle comprising at least one battery pack according to claim 47.

49. A current collector plate electrically connecting a battery cell terminal on a closure of a battery can of a cylindrical battery cell according to claim 1 with an electrode assembly, the current collector plate comprising: a frame portion; a non-coated area coupling portion configured to extend inwardly from the frame portion and coupled with a non-coated area of the electrode assembly; a terminal coupling portion spaced apart from the non-coated area coupling portion with a space therebetween; a connection portion configured to extend inwardly from the frame to connect to the terminal coupling portion; and a fuse portion formed on the connection portion and having a greater resistance than other areas under the same current application.

50. The current collector plate of claim 49, the frame portion has a frame shape with an internal space therein, and wherein wherein the non-coated area coupling portion and the terminal coupling portion are formed in the internal space of the frame portion.

51. The current collector plate of claim 49, the non-coated area coupling portion and the terminal coupling portion are electrically connected by means of the frame portion and the connection portion. wherein 52. The current collector plate of claim 49, the terminal coupling portion is located at the center of the internal space of the frame portion. wherein ​

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